# Incoming Phone Number Assigned Add-ons Extensions Subresource

This endpoint allows Add-on Listing users to fetch an [Extension](/docs/marketplace/api/available-add-ons-extensions) or view a list of Extensions associated with an assigned Add-on Listing of a Twilio phone number.

When an Add-on Listing is assigned to a Twilio phone number, it is only invoked for communications associated with that phone number rather than the entire Account.

> \[!NOTE]
>
> This API only supports Add-on Listings that are in General Availability (GA) or Beta state. Listings that are labeled as Coming Soon or Developer Preview are not accessible via the API and must be managed in the Console.

## Extension Properties

```json
{"type":"object","refName":"api.v2010.account.incoming_phone_number.incoming_phone_number_assigned_add_on.incoming_phone_number_assigned_add_on_extension","modelName":"api_v2010_account_incoming_phone_number_incoming_phone_number_assigned_add_on_incoming_phone_number_assigned_add_on_extension","properties":{"sid":{"type":"string","minLength":34,"maxLength":34,"pattern":"^XF[0-9a-fA-F]{32}$","nullable":true,"description":"The unique string that that we created to identify the resource."},"account_sid":{"type":"string","minLength":34,"maxLength":34,"pattern":"^AC[0-9a-fA-F]{32}$","nullable":true,"description":"The SID of the [Account](/docs/iam/api/account) that created the resource."},"resource_sid":{"type":"string","minLength":34,"maxLength":34,"pattern":"^PN[0-9a-fA-F]{32}$","nullable":true,"description":"The SID of the Phone Number to which the Add-on is assigned."},"assigned_add_on_sid":{"type":"string","minLength":34,"maxLength":34,"pattern":"^XE[0-9a-fA-F]{32}$","nullable":true,"description":"The SID that uniquely identifies the assigned Add-on installation."},"friendly_name":{"type":"string","nullable":true,"description":"The string that you assigned to describe the resource.","x-twilio":{"pii":{"handling":"standard","deleteSla":30}}},"product_name":{"type":"string","nullable":true,"description":"A string that you assigned to describe the Product this Extension is used within."},"unique_name":{"type":"string","nullable":true,"description":"An application-defined string that uniquely identifies the resource. It can be used in place of the resource's `sid` in the URL to address the resource."},"uri":{"type":"string","nullable":true,"description":"The URI of the resource, relative to `https://api.twilio.com`."},"enabled":{"type":"boolean","nullable":true,"description":"Whether the Extension will be invoked."}}}
```

## Fetch an instance of an Extension for the Assigned Add-on.

`GET https://api.twilio.com/2010-04-01/Accounts/{AccountSid}/IncomingPhoneNumbers/{ResourceSid}/AssignedAddOns/{AssignedAddOnSid}/Extensions/{Sid}.json`

### Path parameters

```json
[{"name":"AccountSid","in":"path","description":"The SID of the [Account](/docs/iam/api/account) that created the resource to fetch.","schema":{"type":"string","minLength":34,"maxLength":34,"pattern":"^AC[0-9a-fA-F]{32}$"},"required":true},{"name":"ResourceSid","in":"path","description":"The SID of the Phone Number to which the Add-on is assigned.","schema":{"type":"string","minLength":34,"maxLength":34,"pattern":"^PN[0-9a-fA-F]{32}$"},"required":true},{"name":"AssignedAddOnSid","in":"path","description":"The SID that uniquely identifies the assigned Add-on installation.","schema":{"type":"string","minLength":34,"maxLength":34,"pattern":"^XE[0-9a-fA-F]{32}$"},"required":true},{"name":"Sid","in":"path","description":"The Twilio-provided string that uniquely identifies the resource to fetch.","schema":{"type":"string","minLength":34,"maxLength":34,"pattern":"^XF[0-9a-fA-F]{32}$"},"required":true}]
```

Fetch an Extension

```js
// Download the helper library from https://www.twilio.com/docs/node/install
const twilio = require("twilio"); // Or, for ESM: import twilio from "twilio";

// Find your Account SID and Auth Token at twilio.com/console
// and set the environment variables. See http://twil.io/secure
const accountSid = process.env.TWILIO_ACCOUNT_SID;
const authToken = process.env.TWILIO_AUTH_TOKEN;
const client = twilio(accountSid, authToken);

async function fetchIncomingPhoneNumberAssignedAddOnExtension() {
  const extension = await client
    .incomingPhoneNumbers("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .assignedAddOns("XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .extensions("XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .fetch();

  console.log(extension.sid);
}

fetchIncomingPhoneNumberAssignedAddOnExtension();
```

```python
# Download the helper library from https://www.twilio.com/docs/python/install
import os
from twilio.rest import Client

# Find your Account SID and Auth Token at twilio.com/console
# and set the environment variables. See http://twil.io/secure
account_sid = os.environ["TWILIO_ACCOUNT_SID"]
auth_token = os.environ["TWILIO_AUTH_TOKEN"]
client = Client(account_sid, auth_token)

extension = (
    client.incoming_phone_numbers("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .assigned_add_ons("XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .extensions("XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .fetch()
)

print(extension.sid)
```

```csharp
// Install the C# / .NET helper library from twilio.com/docs/csharp/install

using System;
using Twilio;
using Twilio.Rest.Api.V2010.Account.IncomingPhoneNumber.AssignedAddOn;
using System.Threading.Tasks;

class Program {
    public static async Task Main(string[] args) {
        // Find your Account SID and Auth Token at twilio.com/console
        // and set the environment variables. See http://twil.io/secure
        string accountSid = Environment.GetEnvironmentVariable("TWILIO_ACCOUNT_SID");
        string authToken = Environment.GetEnvironmentVariable("TWILIO_AUTH_TOKEN");

        TwilioClient.Init(accountSid, authToken);

        var assignedAddOnExtension = await AssignedAddOnExtensionResource.FetchAsync(
            pathResourceSid: "PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
            pathAssignedAddOnSid: "XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
            pathSid: "XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");

        Console.WriteLine(assignedAddOnExtension.Sid);
    }
}
```

```java
// Install the Java helper library from twilio.com/docs/java/install

import com.twilio.Twilio;
import com.twilio.rest.api.v2010.account.incomingphonenumber.assignedaddon.AssignedAddOnExtension;

public class Example {
    // Find your Account SID and Auth Token at twilio.com/console
    // and set the environment variables. See http://twil.io/secure
    public static final String ACCOUNT_SID = System.getenv("TWILIO_ACCOUNT_SID");
    public static final String AUTH_TOKEN = System.getenv("TWILIO_AUTH_TOKEN");

    public static void main(String[] args) {
        Twilio.init(ACCOUNT_SID, AUTH_TOKEN);
        AssignedAddOnExtension assignedAddOnExtension = AssignedAddOnExtension
                                                            .fetcher("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
                                                                "XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
                                                                "XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
                                                            .fetch();

        System.out.println(assignedAddOnExtension.getSid());
    }
}
```

```go
// Download the helper library from https://www.twilio.com/docs/go/install
package main

import (
	"fmt"
	"github.com/twilio/twilio-go"
	api "github.com/twilio/twilio-go/rest/api/v2010"
	"os"
)

func main() {
	// Find your Account SID and Auth Token at twilio.com/console
	// and set the environment variables. See http://twil.io/secure
	// Make sure TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN exists in your environment
	client := twilio.NewRestClient()

	params := &api.FetchIncomingPhoneNumberAssignedAddOnExtensionParams{}

	resp, err := client.Api.FetchIncomingPhoneNumberAssignedAddOnExtension("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
		"XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
		"XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
		params)
	if err != nil {
		fmt.Println(err.Error())
		os.Exit(1)
	} else {
		if resp.Sid != nil {
			fmt.Println(*resp.Sid)
		} else {
			fmt.Println(resp.Sid)
		}
	}
}
```

```php
<?php

// Update the path below to your autoload.php,
// see https://getcomposer.org/doc/01-basic-usage.md
require_once "/path/to/vendor/autoload.php";

use Twilio\Rest\Client;

// Find your Account SID and Auth Token at twilio.com/console
// and set the environment variables. See http://twil.io/secure
$sid = getenv("TWILIO_ACCOUNT_SID");
$token = getenv("TWILIO_AUTH_TOKEN");
$twilio = new Client($sid, $token);

$extension = $twilio
    ->incomingPhoneNumbers("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    ->assignedAddOns("XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    ->extensions("XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    ->fetch();

print $extension->sid;
```

```ruby
# Download the helper library from https://www.twilio.com/docs/ruby/install
require 'twilio-ruby'

# Find your Account SID and Auth Token at twilio.com/console
# and set the environment variables. See http://twil.io/secure
account_sid = ENV['TWILIO_ACCOUNT_SID']
auth_token = ENV['TWILIO_AUTH_TOKEN']
@client = Twilio::REST::Client.new(account_sid, auth_token)

extension = @client
            .api
            .v2010
            .incoming_phone_numbers('PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa')
            .assigned_add_ons('XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa')
            .extensions('XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa')
            .fetch

puts extension.sid
```

```bash
# Install the twilio-cli from https://twil.io/cli

twilio api:core:incoming-phone-numbers:assigned-add-ons:extensions:fetch \
   --resource-sid PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \
   --assigned-add-on-sid XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \
   --sid XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
```

```bash
curl -X GET "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_ACCOUNT_SID/IncomingPhoneNumbers/PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/AssignedAddOns/XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Extensions/XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.json" \
-u $TWILIO_ACCOUNT_SID:$TWILIO_AUTH_TOKEN
```

```json
{
  "sid": "XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  "assigned_add_on_sid": "XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  "resource_sid": "PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  "account_sid": "ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  "friendly_name": "Incoming Voice Call",
  "product_name": "Programmable Voice",
  "unique_name": "voice-incoming",
  "uri": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/IncomingPhoneNumbers/PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/AssignedAddOns/XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Extensions/XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.json",
  "enabled": true
}
```

## Retrieve a list of Extensions for the Assigned Add-on.

`GET https://api.twilio.com/2010-04-01/Accounts/{AccountSid}/IncomingPhoneNumbers/{ResourceSid}/AssignedAddOns/{AssignedAddOnSid}/Extensions.json`

### Path parameters

```json
[{"name":"AccountSid","in":"path","description":"The SID of the [Account](/docs/iam/api/account) that created the resources to read.","schema":{"type":"string","minLength":34,"maxLength":34,"pattern":"^AC[0-9a-fA-F]{32}$"},"required":true},{"name":"ResourceSid","in":"path","description":"The SID of the Phone Number to which the Add-on is assigned.","schema":{"type":"string","minLength":34,"maxLength":34,"pattern":"^PN[0-9a-fA-F]{32}$"},"required":true},{"name":"AssignedAddOnSid","in":"path","description":"The SID that uniquely identifies the assigned Add-on installation.","schema":{"type":"string","minLength":34,"maxLength":34,"pattern":"^XE[0-9a-fA-F]{32}$"},"required":true}]
```

### Query parameters

```json
[{"name":"PageSize","in":"query","description":"How many resources to return in each list page. The default is 50, and the maximum is 1000.","schema":{"type":"integer","format":"int64","minimum":1,"maximum":1000}},{"name":"Page","in":"query","description":"The page index. This value is simply for client state.","schema":{"type":"integer","minimum":0}},{"name":"PageToken","in":"query","description":"The page token. This is provided by the API.","schema":{"type":"string"}}]
```

List multiple Extensions

```js
// Download the helper library from https://www.twilio.com/docs/node/install
const twilio = require("twilio"); // Or, for ESM: import twilio from "twilio";

// Find your Account SID and Auth Token at twilio.com/console
// and set the environment variables. See http://twil.io/secure
const accountSid = process.env.TWILIO_ACCOUNT_SID;
const authToken = process.env.TWILIO_AUTH_TOKEN;
const client = twilio(accountSid, authToken);

async function listIncomingPhoneNumberAssignedAddOnExtension() {
  const extensions = await client
    .incomingPhoneNumbers("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .assignedAddOns("XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .extensions.list({ limit: 20 });

  extensions.forEach((e) => console.log(e.sid));
}

listIncomingPhoneNumberAssignedAddOnExtension();
```

```python
# Download the helper library from https://www.twilio.com/docs/python/install
import os
from twilio.rest import Client

# Find your Account SID and Auth Token at twilio.com/console
# and set the environment variables. See http://twil.io/secure
account_sid = os.environ["TWILIO_ACCOUNT_SID"]
auth_token = os.environ["TWILIO_AUTH_TOKEN"]
client = Client(account_sid, auth_token)

extensions = (
    client.incoming_phone_numbers("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .assigned_add_ons("XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    .extensions.list(limit=20)
)

for record in extensions:
    print(record.sid)
```

```csharp
// Install the C# / .NET helper library from twilio.com/docs/csharp/install

using System;
using Twilio;
using Twilio.Rest.Api.V2010.Account.IncomingPhoneNumber.AssignedAddOn;
using System.Threading.Tasks;

class Program {
    public static async Task Main(string[] args) {
        // Find your Account SID and Auth Token at twilio.com/console
        // and set the environment variables. See http://twil.io/secure
        string accountSid = Environment.GetEnvironmentVariable("TWILIO_ACCOUNT_SID");
        string authToken = Environment.GetEnvironmentVariable("TWILIO_AUTH_TOKEN");

        TwilioClient.Init(accountSid, authToken);

        var assignedAddOnExtensions = await AssignedAddOnExtensionResource.ReadAsync(
            pathResourceSid: "PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
            pathAssignedAddOnSid: "XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
            limit: 20);

        foreach (var record in assignedAddOnExtensions) {
            Console.WriteLine(record.Sid);
        }
    }
}
```

```java
// Install the Java helper library from twilio.com/docs/java/install

import com.twilio.Twilio;
import com.twilio.rest.api.v2010.account.incomingphonenumber.assignedaddon.AssignedAddOnExtension;
import com.twilio.base.ResourceSet;

public class Example {
    // Find your Account SID and Auth Token at twilio.com/console
    // and set the environment variables. See http://twil.io/secure
    public static final String ACCOUNT_SID = System.getenv("TWILIO_ACCOUNT_SID");
    public static final String AUTH_TOKEN = System.getenv("TWILIO_AUTH_TOKEN");

    public static void main(String[] args) {
        Twilio.init(ACCOUNT_SID, AUTH_TOKEN);
        ResourceSet<AssignedAddOnExtension> assignedAddOnExtensions =
            AssignedAddOnExtension.reader("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", "XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
                .limit(20)
                .read();

        for (AssignedAddOnExtension record : assignedAddOnExtensions) {
            System.out.println(record.getSid());
        }
    }
}
```

```go
// Download the helper library from https://www.twilio.com/docs/go/install
package main

import (
	"fmt"
	"github.com/twilio/twilio-go"
	api "github.com/twilio/twilio-go/rest/api/v2010"
	"os"
)

func main() {
	// Find your Account SID and Auth Token at twilio.com/console
	// and set the environment variables. See http://twil.io/secure
	// Make sure TWILIO_ACCOUNT_SID and TWILIO_AUTH_TOKEN exists in your environment
	client := twilio.NewRestClient()

	params := &api.ListIncomingPhoneNumberAssignedAddOnExtensionParams{}
	params.SetLimit(20)

	resp, err := client.Api.ListIncomingPhoneNumberAssignedAddOnExtension("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
		"XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
		params)
	if err != nil {
		fmt.Println(err.Error())
		os.Exit(1)
	} else {
		for record := range resp {
			if resp[record].Sid != nil {
				fmt.Println(*resp[record].Sid)
			} else {
				fmt.Println(resp[record].Sid)
			}
		}
	}
}
```

```php
<?php

// Update the path below to your autoload.php,
// see https://getcomposer.org/doc/01-basic-usage.md
require_once "/path/to/vendor/autoload.php";

use Twilio\Rest\Client;

// Find your Account SID and Auth Token at twilio.com/console
// and set the environment variables. See http://twil.io/secure
$sid = getenv("TWILIO_ACCOUNT_SID");
$token = getenv("TWILIO_AUTH_TOKEN");
$twilio = new Client($sid, $token);

$extensions = $twilio
    ->incomingPhoneNumbers("PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    ->assignedAddOns("XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
    ->extensions->read(20);

foreach ($extensions as $record) {
    print $record->sid;
}
```

```ruby
# Download the helper library from https://www.twilio.com/docs/ruby/install
require 'twilio-ruby'

# Find your Account SID and Auth Token at twilio.com/console
# and set the environment variables. See http://twil.io/secure
account_sid = ENV['TWILIO_ACCOUNT_SID']
auth_token = ENV['TWILIO_AUTH_TOKEN']
@client = Twilio::REST::Client.new(account_sid, auth_token)

extensions = @client
             .api
             .v2010
             .incoming_phone_numbers('PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa')
             .assigned_add_ons('XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa')
             .extensions
             .list(limit: 20)

extensions.each do |record|
   puts record.sid
end
```

```bash
# Install the twilio-cli from https://twil.io/cli

twilio api:core:incoming-phone-numbers:assigned-add-ons:extensions:list \
   --resource-sid PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \
   --assigned-add-on-sid XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
```

```bash
curl -X GET "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_ACCOUNT_SID/IncomingPhoneNumbers/PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/AssignedAddOns/XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Extensions.json?PageSize=20" \
-u $TWILIO_ACCOUNT_SID:$TWILIO_AUTH_TOKEN
```

```json
{
  "end": 0,
  "first_page_uri": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/IncomingPhoneNumbers/PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/AssignedAddOns/XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Extensions.json?PageSize=50&Page=0",
  "next_page_uri": null,
  "page": 0,
  "page_size": 50,
  "previous_page_uri": null,
  "extensions": [
    {
      "sid": "XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
      "assigned_add_on_sid": "XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
      "resource_sid": "PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
      "account_sid": "ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
      "friendly_name": "Incoming Voice Call",
      "product_name": "Programmable Voice",
      "unique_name": "voice-incoming",
      "enabled": true,
      "uri": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/IncomingPhoneNumbers/PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/AssignedAddOns/XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Extensions/XFaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.json"
    }
  ],
  "start": 0,
  "uri": "/2010-04-01/Accounts/ACaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/IncomingPhoneNumbers/PNaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/AssignedAddOns/XEaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/Extensions.json?PageSize=50&Page=0"
}
```